A World Trade Organization (WTO) panel on 22 February upheld most of Japan’s claims challenging South Korea’s ban on importing seafood from eight Japanese prefectures and on additional radionuclide testing requirements.

Japan initially requested consultations on the matter in 2015. The slowness of the ruling was due to the complexity of the matter—Japan claimed violations of a wide range of trade rules—and due to scheduling conflicts between panel members and the need to translate materials into several languages.

South Korea responded to the 2011 Fukushima Dai-ichi Nuclear Power Plant accident in Japan by imposing import bans on specific fishery products from certain Japanese prefectures, similar to measures imposed by other countries after the disaster. However, in 2013, South Korea extended the ban to all fishery products from eight Japanese prefectures.

South Korea’s measures came largely out of frustration with the inconsistency of statements from Japan regarding the incident. Tensions reached a peak when facility operator Tokyo Electric Power Co. (TEPCO) said that it had detected radiation of 2,200 millisieverts an hour at a hotspot near a water tank. Shunichi Tanaka, chairman of Japan's nuclear regulation authority, who was trying to dampen fears during Tokyo's Olympics bid, criticized TEPCO for releasing misleading data about the water leaks. He said the company should have used the unit "Becquerel," which signifies the radioactivity level in the water, rather than "millisieverts," which measures potential human exposure.

South Korea was also alarmed by a release of radioactive cooling water into the Pacific Ocean. It responded by deciding that Japanese data was inadequate and applying its ban on seafood products from Fukushima and seven other prefectures: namely Ibaraki, Gunma, Miyagi, Iwate, Tochigi, Chiba and Aomori, which collectively compose the northern half of the main island of Honshu.

In the WTO ruling, the panel noted that South Korea’s ban is a “blanket ban” on all fishery products, rather than a “selective ban” on only high-risk species. As such, it is considered arbitrary and unjust. Japan has especially called for allowing imports of 28 species, including bonito, saury, and abalone.

Following the WTO ruling, South Korea’s Ministry of Trade, Industry and Energy said in a release that the government would appeal in order to safeguard public health and safety.

“Regardless of the decision, the current import ban will be put in place until the WTO’s dispute settlement procedure ends,” it said.

Under WTO rules, the appeal must be filed within 60 days, or else it becomes final. If South Korea keeps its ban in place after a final ruling in Japan’s favor, Japan would be entitled to take a retaliatory action, such as raising tariffs on South Korean imports.

Japanese Minister of Agriculture, Forestry and Fisheries Ken Saito said at a recent news conference that Japan is seriously considering further action if South Korea doesn’t back down.

“Japan will respond accordingly so that our position will be accepted by the appellate body as well,” Saito said. “We will also call on South Korea to sincerely and promptly correct their measures.”

Fifty-four countries originally placed restriction on Japanese foods after the accident, but only 27 have bans that remain in place today. Among these, China’s restrictions are the closest to those of South Korea. China bans imports of all foods from Tokyo and nine other prefectures.

Taiwan also has a ban on imports of food from several Japanese prefectures, but this may soon be lifted, as it may stand in the way of Taiwan joining the Comprehensive and Progressive Agreement for the Trans-Pacific Partnership (CPTPP), a successor to the Trans-Pacific Partnership agreement that was being negotiated before U.S. President Donald Trump pulled the United States out of negotiations. Japan has requested that Taiwan base its rules on science rather than “unfounded fears.” However, there was an incident in which Japanese exporters mislabeled the origin of its foods to avoid the bans, sowing public mistrust of Japanese foods. As a result, there is strong public sentiment—particularly amongst Taiwan’s opposition Kuomintang Party—against lifting the ban.

Meanwhile, on 28 February, Thailand became the first country to receive a shipment of seafood from Fukushima Prefecture following the accident. The shipment was 110 kilograms of fresh flounder.

Japanese fishermen in Fukushima began trial-fishing in June 2012. According to prefectural officials, since April 2015, no seafood has been found with radiation levels exceeding Japan’s safety standards. In March of 2017, the prefecture's fisheries association reduced its voluntary fishing exclusion zone from 20 to 10 kilometers away from the nuclear plant.